Lapping machine



Dec. 1938- G. E. HULBERT ET AL 2,142,057

LAPPING MACHINE Filed May 25, 1936 2 Sheets-Sheet 1 7 20 1 r I 1! j H| 14 l I /5 B I! P I:

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v HERBERT S. INDEE Dec. 27, 1938. G. E. HULBERT ET AL LAPPING MACHINE Filed May 23, 1936 2 Sheets-Sheet 2 GEORGE E. HUL BERT HERBERT S. I NDEE illllllll .5. WIIIIIIIIIIIIIII ll l lm \Wlfifil I IliI'IIIIIa;

Patented Dec. 27, 1938 UNITED STATES PATENT oFFics LAPPING MACHINE setts Application May 23,

2 Claims.

This invention relates to lapping machines, and more particularly to an improved work cage construction therefor.

One object of this invention is to provide a 5 simple thoroughly practical lapping machine. Another object of the invention is to provide a lapping machine witha work carrying cage which is arranged to facilitate rapid removal and loading of work pieces. Another object of this invention is to provide an improved cage for a lapping machine which may be readily loaded from a single operating station. A further object of the invention is to provide a cage construction in which the cage may be readily indexed to facilitate loading the same from a single station in front of the machine. Other objects will be in part obvious or in part pointed out hereinafter.

I This invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

Figure l is a side elevation of a lapping machine, having parts broken away and shown in section to more clearly show the construction;

Figure 2 is a plan view, on an enlarged scale, of the work carrying cage, having parts broken away and shown in section to more clearly show the construction; 7

Figure 3 is a cross sectional View, taken approximately on the line 3--3 of Figure 2;

Figure 4 is a fragmentary plan view, on an enlarged scale, of a modified form of locking device for the work carrying cage; and

Figure 5 is a fragmentary cross sectional view, taken approximately on the line 55 of Figure 4.

A lapping machine has been illustrated in the drawings which comprises a base Iii having a vertically extending support I l on which is mounted a supporting arm [2 for an upper lapping wheel l3. The lapping wheel i3 is supported by a plate M which is fixed to the lower end of a slidably mounted rack bar [5. The upper lap l3 may be raised and lowered by means of a spoked wheel I6 which is mounted on one end of a rotatable shaft ll, The shaft ll carries a gear (not shown) which meshes with the teeth on the rack bar l5 and serves, when the spoked wheel I6 is rotated, to raise or lower the upper lap l3.

In order to hold the lapping wheel 13 in an 1936, Serial No. 81,372-

upper or inoperative position, a ratchet wheel 20 is mounted on the end of the shaft fl and is arranged to be engaged by a pawl 2| pivotally mounted on a stud 22 which is supported on the arm 12.

A lower lapping wheel 30 is supported by a flanged plate 3| which is keyed to a rotatable sleeve 32 which is journaled in bearings 33 and 34 in the base It]. The sleeve may be rotated in the manner shown in the prior United States patent to Indge No. 1,610,527, to which reference may be had for a more detailed disclosure. A tight pulley 35 and a loose pulley 36 are mounted on the outer end of a drive shaft 35 which is rtatably supported in bearings 3! and 3B in the base 10. The shaft 36 carries a worm 3i! which meshes with a worm gear 40 keyed to the rotatable sleeve 32. When a driving belt (not shown) is shifted from the loose pulley 36' onto the tight pulley 35, the shaft 35 and worm 39 are rotated, thereby transmitting a rotary motion to the sleeve 32, the plate 3! and the lower lap 30.

A cage structure 49 is mounted between the lapping wheel 13 and the lapping wheel 38 and is provided with apertures which are shaped to re ceive Work pieces to be lapped. As shown inFigure 2, the cage structure 49 is provided with a plurality of circular work receiving apertures t which serve to locate and hold a plurality of work pieces 52 withinthe cage structure 49 for a lapping operation, The apertures 5| may be square or of any other irregular shape which may correspondin design with the shape of the work piece to be lapped.

In order to provide a desired lapping action between the work pieces and the relatively rotated lapping elements, the cage structure 49 is provided with a mechanism for gyrating the work carrying cage 50 so as to continuously change the relation of the work and the relatively rotatable lapping wheels. For this purpose, a head 55 is keyed to the upper end of a rotatable sleeve 55, the rotatable sleeve 56 being provided with bearings 5'! and 58 which rotatably fit on a stationary vertically extending shaft 59 which is keyed to a projection 50 of the base. The sleeve 56 is mounted in bearings til and 62 which are supported in the rotatable sleeve 32 so that the sleeves 32 and 56 may rotate relativeto each other and relative to the stationary central shaft- 59.

A gear 65 is keyed to the lower end of sleeve 32 and meshes with a gear 66 which is keyed to a bushing 61 rotatably mounted on a fixed stud 68. A gear 69 is also keyed to the bushing 61 and meshes with a gear 10 which is keyed to the lower end of the inner sleeve 56 and serves to rotate the head 56 at a slightly different speed from the rotation of the lap 30.

A gear I is keyed to the upper end of the stationary shaft 59 and meshes with a plurality of spaced pinions II which are rotatably supported on studs I2. The studs I2 are mounted on the rotatable head 55. The pinions II are formed integral with rotatable heads I3 each of which carries a driving or crankpin I4. In the construction illustrated, there are three pinions II which are symmetrically spaced about the central shaft 59 and each of which carries a crankpin I4 which are arranged to engage apertures I5 (Fig. 3) within the cage 50. When the drive shaft 35 is rotated to transmit a rotary motion to the lower lap 30, the rotation of the sleeve ,32 transmits a rotary motion through the gear 65, the gear 66, the gear 89, the gear I0 and the sleeve 58 to rotate the head 55 which serves to revolve the studs 12 about the central stationary shaft 55. The geared connection between the stationary shaft and the heads I3, which includes the gear I0 keyed to the upper end of the shaft, serves to rotate the pinions II during the revolution of the studs I2 and cause a rotation of the heads I3 to transmit a combined rotary and gyrating movement to the cage to carry the work pieces through an irregular path between the lapping wheels for a lapping operation. The construction thus far described is identical with that shown in the prior patent to Indge No. 1,610,527 dated December 14, 1926, to which reference may be had for a more detailed disclosure.

While the machine illustrated and above described shows an upper stationary lap which is moved vertically toward and from a lower rotatable lap, this invention is equally applicable to other types of lapping machines in which either or both of the lapping wheels are rotatable and movable toward and from each other.

In the operation of a lapping machine, especially a lapping machine-in-which the cage and the lapping wheels are of relatively large diameter, it is desirable to provide a means for readily loading the cage, that is removing the finish lapped work pieces therefrom after a lapping operation and inserting new pieces of work in the machine from a single operating station in front of the machine, thereby facilitating the loading of the machine. In the preferred construction, the cage structure 49 is preferably formed in two parts, an outer work carrying cage 50 which is provided with work receiving apertures 5|, .and an inner supporting member I9. The supporting member "I9 comprises a pair of spaced plates 80 and 8| which are held in spaced relationship wth each other by means of a plate 82. The plates 80, BI and 82 are held in fixed relationship with each other by studs 83 which pass through holes in the plates. The three plates 80, 8| and 82 form an annular groove 84 which serves to rotatably support the work carrying cage 50.

It is desirable to provide a suitable driving connection between the work carrying cage 50 and the central supporting member I9 so that during a lapping operation, the work carrying cage 50 and its inner supporting member 19 may be rotated and gyrated simultaneously by the mechanism above described. The work carrying cage .50 is provided with an inner internal aperture 85 which is a clearance hole therethrough so as to permit free rotation of the work carrying cage 50 relative to the supporting member I9.

In the preferred construction, a pawl and ratchet mechanism is interposed between the work carrying cage 50 and its central supporting plates 80, 8| and 82. The work carrying cage 50 is provided with a plurality of notches 81 which arearranged to be engaged by'aplurality of spaced pawls 88 which are pivotally mounted on studs 89. A spring 90 is carried by the inner plate 82 and is arranged to exert a pressure tending to turn the ratchet pawls 88 in a clockwise direction to hold the pawls 88 in engagement with the notches 81 so that when the supporting member I0 is rotated in the direction of the arrow,

provided with a pin receiving aperture I5 which are adapted to engage the driving pins I4. The bushings I00 pass through the three plates 80, 8| and 82 and are held in adjusted position therein by means of nuts IOI. Each of the bushings I00 is provided with an adjusting screw I02 which is adapted to bear against the upper end of the crankpin I4 and serves to adjust the position of the supporting member I9 and work carrying cage 50 relative to the lower lap so that the work carrying cage 50 may be adjusted close to or spaced from the operative surface of the lap 30, depending upon the thickness of the work pieces which are to be lapped. The adjusting screws I02 are held in adjusted position by lock nuts I03 so that after the screws have been adjusted to position the work carrying cage 50, as desired, the locking nuts I03 may be tightened to lock the cage in its adjusted position.

After the lapping operation has continued on a plurality of work pieces 52 so that they have been lapped to the desired extent, the rotation of the lapping wheels I3 and 30 is then stopp d by shifting the driving belt (not shown) from the tight to the loose pulley, and the wheels are thereafter separated from each other. The work piece adjacent to the loading station is then removed from the machine and a new piece of work 52 is inserted thereinstead, and the work'carrying cage 50 may'then be rotated relative to the supporting member I9, by manually rotating the work carrying cage 50 against the ratchet pawls 88 in a counterclockwise direction (Fig. 2) so that the next cage aperture may be loaded from the same position in front of the machine. After the second station has been loaded, the work carrying cage 50 may be further rotated, and so on until all of the finish lapped pieces have been removed and new pieces to be lapped inserted thereinstead for another lapping operation.

A modified form of locking device has been illustrated in the modification shown in Figures 4 and 5. As indicated in the modification, the work carrying cage 50 is provided with a notch or recess I20 which is arranged to be engaged by a slidable plunger I2I which slides within a radially extending slot I22 in the plate 82. The plunger or locking pin I2I is connected by a pivot pin I 23 with a strap I24 which surrounds a rotatable eccentric plate I25. The eccentric plate I25 is rotatably supported between the plates 80 and 8|. A projecting hub I25 serves as a trunnion to support the upper end of the eccentric pla and a Stud 11 passing through an'aperture.

in the lower plate BI serves as a trunnion to rotatably support the eccentric I25. When it is desired to lock the supporting member I9 and the work carrying cage together for a lapping operation, a manually operable handle I30 is moved into the full line position, as shown in Figure 4, so that the eccentric plate I25 moves the plunger I2I downwardly into engagement with the notch I20 so as to lock the work carrying cage 50 to the plates 80, BI and 82 so that they may be rotated and gyrated simultaneously. When the work pieces have been lapped to a predetermined extent, and the laps have been separated to an inoperative position, the handle I30 is moved into the dotted line position I3Ila (Fig. 4) which serves to rotate the eccentric I25 into the dotted line position I25a and thereby to withdraw the plunger I 2I from the notch I20 so that the work carrying cage 50 may be rotated relative to the supporting member I9 for unloading and loading of work pieces.

The operation of this lapping machine is readily apparent from the foregoing disclosure. Assuming the lapping wheels I3 and 30 to be separated in an inoperative position, the work carrying cage 5!] is rotated manually relative to the supporting member 19 from an operating station in front of the machine and a work piece 52 is inserted in each of the apertures 5!, after which the driving belt is shifted from the loose to the tight pulley to start a relative rotation between the lapping wheels and at the same time to start the rotation and gyration of the supporting member 19 and the work carrying cage 50 to simultaneously lap a plurality of work pieces to a predetermined extent. After the work pieces have been lapped to the required extent, the laps are again relatively separated from the work pieces and the lapped work pieces are removed therefrom and new pieces inserted therein as the Work carrying cage 50 is rotated relative to the supporting member I9, thereby facilitating loading of the machine and enabling a machine of large diameter to be loaded from a single operating station in front of the machine.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

A divisional application Serial No. 208,629 was filed on May 18, 1938, covering the subject matter of the disclosure illustrated in Figs. 4 and 5.

We claim:

1. A lapping machine comprising a pair of opposed relatively rotatable lapping wheels, means to relatively rotate said wheels, means to move said wheels relatively toward and from each other, a cage supporting member, means to rotate and gyrate said cage supporting member, a work carrying cage rotatably supported thereon, and means including a pawl and ratchet mechanism which serves to gyrate said cage for a lapping operation, and which is arranged so that the cage may be indexed manually to facilitate loading of work pieces.

2. A work support for a lapping machine comprising a central supporting member which is arranged for an irregular movement, a work carrying cage having a plurality of work receiving apertures which is rotatably supported thereon, and means including a plurality of pawls on said supporting member and a plurality of notches on said cage to drive said work carrying cage when the supporting member is moved through an irregular path, said pawls being arranged to permit rotation of said cage in one direction when the supporting member is stationary to facilitate loading of work pieces into said apertures in the cage.

GEORGE E. HULBERT. HERBERT S. INDGE. 

